NOTE ON SCF CALCULATIONS OF VALENCE LEVELS IN HEAVY MOLECULES

Using a one-component relativistic theory we have recently developed, we illustrate some interesting features of self-consistent field (SCF) relativistic one-electron calculations. In particular, it is demonstrated that nonrelativistic calculations of valence levels in actinide atoms and in molecules containing actinide atoms in which only the core states are treated relativistically, do not agree with fully relativistic results. Also it is found that if only the heavy atom(s) of a molecule is treated relativistically one obtains excellent agreement with a fully relativistic calculation. Non-SCF relativistic calculations (using self-consistent nonrelativistic potentials) are shown to give results equivalent to those obtained from first order perturbation theory. The differences between effects due to the relativistic portions of the Hamiltonian (direct) and effects due to the SCF process (indirect) are given for both atoms and molecules. The three examples used are the uranium atom, the UF6, and UO22+ molecules. All calculations were performed using the local exchange approximation. © 1979 American Institute of Physics.